It is known to use a saw blade attached to a platform to score or cut grooves in "soft" concrete to relieve stress as the latter dries. ("Soft" concrete is newly poured concrete, occurring after "bull floating" and finishing has been completed, but before stress due to drying has occurred.)
The dimensions of the groove: about 1 inch in depth by about 3/16 inches in width. The length varies. Its purpose: to control direction and extent of cracking of the concrete. This is because the grooves in the soft concrete provided weakened planes. Such planes pass usually vertically through the grooves. Hence as the concrete cures and shrinks, the cracks are along such planes but since they begin at the trough of the groove, such cracks are not visible at the surface of the slab.
In U.S. Pat. No. 4,769,201, there is described such a concrete saw. Rollers are attached to three corners of a base plate. But because of need to add pressure about the rotating blade as the cut is made (usually, to prevent "spalding" (irregular side edges) of the cut, a pressure plate is attached to the fourth corner inline with the push pole. Since the pressure plate, and blade are cantilevered from the platform outside the rolling plane of the single inline roller (i.e., outside a horizontal plane through the roller), experience shows that a sidewise torque is imparted to the blade and pressure plate. Hence, the device in some cases as where the concrete has a large number of surface rocks, may be difficult to control. Also, a large amount of the dust is emitted as cutting occurs often obscuring the pre existing line of sight guiding the user. Dry cutting of dried, firm concrete is also difficult because of these factors. In addition, the position of the rollers plus pressure plate vis-a vis the saw blade position of maximum penetration, requires the use of a separate entry and exiting platform at the edge of the stab to begin and end the cut.